562 



Garden and Forest. 



[November 20, 1889. 



species which form it, the soil-conditions and several other 

 factors. Some species, like the Beech, Fir and Spruce, have 

 the capacity to develop their leaves, and vegetate with very 

 little light at their command ; others, like Birches, Poplars, 

 Ashes, require much light, and therefore thin out very soon 

 under their own shade, exerted by their crown. The for- 

 mer class, which may be called shade-enduring timbers, 

 can develop in about hfty to seventy-five per cent, of the 

 room which the latter, the light-needing, require for full 

 development. This means that fewer individuals of the 

 latter are allowed to live on a given area than of the former, 

 and the natural cleaning of dead branches takes place much 

 more rapidly, and earlier. 



On the better qualities of soil this struggle for existence is 

 brought to a close much sooner than on poorer land and in 

 higher altitudes, where the energy of growth is less vigor- 

 ous. Therefore, we can say, summarily, that in a normal, 

 natural forest growth, the average room occupied per tree 

 is larger in proportion as the growth is older, the species 

 more light-needing, the soil conditions better and the locality 

 less elevated. 



The treatise on pruning forest and ornamental trees, by 

 Des Cars, translated by Professor Sargent, contains all in- 

 formation necessary as to the methods of pruning. Where 

 walling over of the wound is expected, it may be said 

 that if the pruning is done in July rather than in the 

 autumn the healing process will begin the first season, and 

 to some extent the danger of frost to the wound will be 

 avoided. The main point is to cut with a fine-toothed saw as 

 close as possible to the trunk, taking care to make a 

 smooth, uniform cut, and to avoid loosening the bark ; 

 this necessitates, in heavy branches, two cuts, the first lop- 

 ping the branch at a distance from the trunk to relieve the 

 weight. Conifers usually furnish the water-proof coat by 

 the exudation of resin. Deciduous trees require artificial 

 protection by means of coal-tar thinned with turpentine 

 and applied with a brush. 



How far pruning ma}^ be depended upon to produce 

 timber free from knots is still an open question, and de- 

 pends on circumstances often beyond our control. 

 Washington, D.c. B.E.Femow. 



Ocneria dispar. 



To the Editor of Garden and Forest : 



Su". — hi the Boston Evejting Transcripi oiOcioher 2i'^sti\\erQ is 

 an article headed " -Save the Trees " givingsomeaccountof this 

 European moth, which has become seriousl)' aljundant at 

 Medford, Massachusetts. The writer of the article states that 

 the insects were " first noticed three or four years ago. . . . 

 For a while the extent of their work was so limited tliat not 

 much attention was paid to them, but early last summer tlieir 

 numbers had so increased that much damage was caused." 



Although there can be no doubt tliat the insect will commit 

 serious ravages, if unchecked in any way, the prospect that 

 " a great danger threatens the country unless prompt and 

 effective measures are taken to stamp out the pest " seems 

 remote, when it is known that over twenty years have elapsed 

 since it was accidentally introduced by M. L. Trouvelot, a 

 French naturalist, who made experiments in silk raising near 

 Medford, but whose efforts in this direction were unsuccess- 

 ful, partly because he also unintentionally imported one of the 

 diseases so fatal to the silk worm. This Ocneria (also known 

 under the generic names Hypogymna and Liparis) is nearly 

 allied to the troublesome tent-caterpillar (Clisiocampa), and to 

 the Orgyia, which is often so destructive to the foliage of many 

 of our shade trees. 



The males and females of the species differ strikingly. Tiie 

 former are small bodied, with dark reddish brown wings, 

 which expand about an inch and a half, and the large bodied 

 females have white or greenish white wings, witli black and 

 brown markings. They expand about two and one-half inches. 



The egg masses are deposited on the limbs of the plants 

 upon whicli the caterpillars feed. When fully grown the lat- 

 ter are larger than our common tent-caterpillar (Clisiocampa), 

 and are dark in color and sparingly covered with small tufts 

 of long hairs. They are almost omnivorous in their feeding- 

 habits and in Europe they eat the foliage of such differing 

 plants as the Apple, Peach, Linden, Azalea, Oak, Larch, Juniper 

 and White Pine. 



In the article in the Traiiscript it is stated that the State 

 Board of Agricidture "intends to ask the Legislature for an 

 appropriation sufficient to meet tlie emergency," and it seems 

 to be expectetl that a lil)eral aj^propriation will exterminate 

 the pest. 



Professor Fernald, the Entomologist of tlie Hatch Experi- 

 ment Station, is also said to be preparing circulars, illustrated 

 liy plates, which " will be sent to all the residents of Medford 

 in order that they may watch for the re-appearance of the pest 

 and co-operate in the work of stamping it out." The outcome 

 of these efforts will be very interesting. 



It is, at least, very improbable that every specimen in such 

 a considerable area (about one and a half square miles, ac- 

 cording to the article quoted) can be destroyed. The insect 

 has probably come to stay, and, ultimately, the best way to 

 keep it in check, outside of the artificial remedies, may be the 

 importation of the parasites and natural enemies to which it 

 is liable in Europe. 



European specimens of the insect in all its stages have been 

 for many years on exhibition at tlie Zoological Museum, at 

 Cambridge, Massachusetts. One of the earliest notices of its 

 introduction occiu^s in \.\\& American Entomologist, vo\. ii., p. in 

 (February, 1870), and the case is also mentioned in Professor 

 Riley's report on the insects of Missouri for the same year. 



Caiuliridge. Qllls. 



Exhibitions. 



The Chrysanthemum Show at Philadelphia. 



r^ ARDENERS complain that this has been a trying year for 

 ^^ Chrysanthemums, and yet the collection of plants in Hor- 

 ticidtural Hall last week was one of the largest ever shown 

 there, and, beyond question, the best in quality. Not only 

 were the plants exceptionally good, butthey were well arranged 

 and displayed. They were not placed in a solid mass, but were 

 separated into two sections by a broad wall of green which ran 

 lengthwise through the middle of the hall.. This stretch of 

 green began near the entrance with a remarkable collection of 

 Ferns on a low table, beyond which towered a superb Cibotliim 

 regale. Then came tall Palms, with branches overarching a 

 mound of rich foliage, while further on, the low tables, covered 

 with Marantas, Draca?nas and plants of this class, stretched 

 toward the stage. The bank of Palms across the stage-front, 

 like the Ferns, from the gardens of Mr. A. J. Drexel, were all 

 good examples of choice kinds like Pritchardla grajidis and 

 Llvistoiiia Chinensis aiirea. Around the whole the walls were 

 hung with evergreen and autumn leaves, and the galleries 

 were wreathed and festooned with garlands of the same. 



All this made an admirable frame and setting for the long 

 double rows of flowering plants on either side of the hall. 

 These were in great variety, including the best known of tlie 

 old kinds of established reputation and a strong showing of 

 later introductions. Among the plants and cut blooms were 

 examples of some forty kinds which had never been exhibited 

 before. It is worth putting on record, too, that of the plants 

 and tlowers, both old and \\&\y, which attracted most attention, 

 at least one out of every four, and perhaps a still larger pro- 

 portion, were originated by Mr. W. K. Harris. Beyond doubt 

 the seedling Chrysanthemums of the first quality which, as 

 tlie product of Mr. Harris' skill, now enrich our gardens, far 

 outnumber those originated by any other American. 



Among the plants the group of twelve, which took the prize 

 for the best collection of that number, displayed wonderful 

 cultural skill. These plants are naturally of different habit and 

 time of blooming, and yet they were all at their very best on 

 this special occasion, and while they had not been tortured 

 into any formal shapes, they were surprisingly even in size and 

 proportion — that is, about three feet high and five feet across, 

 with a fully developed fiower, erect on every branchlet. There 

 were better single plants in the room than any individual of 

 this dozen, but every one was a striking specimen, and all were 

 so uniformly vigorous and floriferous that one looking down 

 upon them would find it difficult to point out in what particu- 

 lar any one of them was more satisfactorily grown than 

 another. As a matter for future reference, we give the names 

 of this prize list : Mrs. A. Blanc, Gold, Mrs. Irving Clarke, Miss 

 May Wheeler, Frank Wilcox, Mrs. Frank Thompson, Robert 

 Crawford, Robert Bottomly, Puritan, Grandifiorum, Bride, and 

 W. H. Lincoln. Of these all but three are American seed- 

 lings. They were exhibited by James Verner, gardener to A.J. 

 Drexel. Of other plants, one of tlie most interesting was a 

 specimen of Mrs. William Bowen, carrying about a hundred 

 blooms, with florets of an intense crimson within and bronze 

 reverse. Very striking, too, was a plant of Mrs. Irving Clarke, 



